The human visual system is capable of identifying and processing visual features with High Dynamic Range. For example, real-world scenes with contrast ratios of 1,000,000:1 or greater can be accurately processed by the human visual cortex. However, most image acquisition devices are only capable of reproducing or capturing Low Dynamic Range, resulting in a loss of image accuracy. The problem is ever more significant in video imaging.
There are examples of creating High Dynamic Range images by post processing images from multiple sensors, each of different exposures. The resulting “blended” image is intended to capture a broader dynamic range than would be possible from a single sensor without a post-processing operation. However, the required post-processing is time-intensive and produces an HDR video signal that requires an expensive HDR playback device and display device.
The requirement for intensive post-processing and uncommon equipment leads to HDR video systems that are not well suited to how many people watch television. For example, live broadcasts are an important part of television. Many people follow the news or their favorite sports teams by watching events live, whereas existing HDR video production requires filming followed by post-production processing and then display. Additionally, some HDR video systems are not backwards-compatible with the existing installed base of users who have low dynamic range (LDR) televisions.